Pipe conditioning tool

Abstract

A pipe conditioning tool comprising a drive unit to move the tool along a pipe and a work head rotatable about an axis of the pipe to condition a surface of the pipe, the drive unit includes a frame extending to opposite sides of the pipe, the frame having legs extending radially beyond the work head to provide support for the tool upon removal from said pipe.

The invention claimed is: 
     
       1. A pipe conditioning tool comprising a drive unit to move said tool along a pipe and a work head configured to rotate by said drive unit about an axis of said pipe to condition a surface of said pipe, said drive unit including a frame including a pair of yokes, each having a bight extending across said pipe and a pair of legs extending from said bight at a spacing to accommodate said pipe, said legs extending to opposite sides of said pipe, a pair of arms pivotally connected to said frame on opposite sides of said pipe and moveable about a longitudinal axis to said pipe to engage said pipe to secure said frame to said pipe, said arms each having wheels connected thereto to engage said pipe and to support said frame for movement along said pipe, said arms being configured to move from an open position aligned with said legs to permit said pipe to pass between said arms to a secure position in which said arms extend toward one another from said legs to encompass said pipe, said legs extending radially beyond said work head and said arms to provide support for said tool upon removal from said pipe, said drive unit further including a ring gear having radially inwardly directed gear teeth and a plurality of guide rollers spaced apart about said ring gear and engaging said gear teeth, a drive gear engaging said ring gear and rotatable by a drive motor to impart rotation to said ring gear, said work head being connected to said ring gear for movement therewith. 
     
     
       2. A pipe conditioning tool according to  claim 1  wherein said arms are pivotally connected to said frame adjacent said bight. 
     
     
       3. A pipe conditioning tool according to  claim 1  wherein a flexible releasable fastener extends between said arms to hold said wheels in engagement with said pipe. 
     
     
       4. A pipe conditioning tool according to  claim 1  wherein a drive roller is mounted on said frame for engagement with said pipe. 
     
     
       5. A pipe conditioning tool according to  claim 4  wherein a pair of drive rollers are provided at spaced locations on said frame. 
     
     
       6. The pipe conditioning tool according to  claim 1  wherein a plurality of work heads are circumferentially spaced about said ring gear. 
     
     
       7. The pipe conditioning tool according to  claim 1  wherein each of said guide rollers includes a hub and a pair of flanges on opposite sides of said hub, said ring gear being received between said flanges. 
     
     
       8. The pipe conditioning tool according to  claim 1  wherein a pair of guide wheels engage a lateral face of said ring gear at circumferentially spaced locations to support said ring gear during rotation. 
     
     
       9. A pipe conditioning tool according to  claim 1 , wherein said drive motor is reversible to impart rotation in opposite directions about said pipe and cause said working head to oscillate about said pipe. 
     
     
       10. A pipe conditioning tool according to  claim 1  wherein reversal of said drive motor is controlled by a limit switch operable to ascertain angular disposition of said ring gear. 
     
     
       11. A pipe conditioning tool according to  claim 10  wherein said limit switch includes a signal generating member carried by said ring gear and circumferentially displaceable on said ring gear between a pair of positions. 
     
     
       12. A pipe conditioning tool according to  claim 1 , a said work head is located in a shroud, said shroud being configured to rotate with said ring gear about an axis of said pipe, said shroud including a collection zone to receive material removed from said pipe, an outlet to remove material from said collection zone, and a rod moveable through said collection zone toward and away from said outlet. 
     
     
       13. A pipe conditioning tool according to  claim 12 , wherein said collection zone includes a tubular member connected to said outlet and said rod moves along said tubular member. 
     
     
       14. A pipe conditioning tool according to  claim 13  wherein said rod is a clearance fit in said tubular member. 
     
     
       15. A pipe conditioning tool according to  claim 14  wherein said rod includes an enlarged head. 
     
     
       16. A pipe conditioning tool according to  claim 12  wherein said rod is moved by a linear actuator through said collection zone. 
     
     
       17. A pipe conditioning tool according to  claim 1  including a reversible drive to rotate said work head relative to said drive unit about said pipe, the direction of rotation of said work unit being controlled by a limit switch responsive to the angular disposition of said work head to said drive unit, said limit switch including a signal generating member configured to rotate with said work head and circumferentially displaceable relative thereto between a pair of positions. 
     
     
       18. A pipe conditioning tool according to  claim 17  wherein said signal generating member is a bar pivotally connected said ring gear and rotatable about said pivot between said pair of positions. 
     
     
       19. A pipe conditioning tool according to  claim 18  wherein said bar carries a signal generator at a location remote from said pivot and said signal generator trails said pivot in the direction of rotation.